import os import streamlit as st import requests from bs4 import BeautifulSoup from sentence_transformers import SentenceTransformer, util from transformers import pipeline class URLValidator: """ A production-ready URL validation class that evaluates the credibility of a webpage using multiple factors: domain trust, content relevance, fact-checking, bias detection, and citations. """ def __init__(self): # SerpAPI Key self.serpapi_key = os.getenv("SERPAPI_KEY") # Load models once to avoid redundant API calls self.similarity_model = SentenceTransformer('sentence-transformers/all-mpnet-base-v2') self.fake_news_classifier = pipeline("text-classification", model="mrm8488/bert-tiny-finetuned-fake-news-detection") self.sentiment_analyzer = pipeline("text-classification", model="cardiffnlp/twitter-roberta-base-sentiment") def fetch_page_content(self, url: str) -> str: """ Fetches and extracts text content from the given URL. """ try: response = requests.get(url, timeout=10) response.raise_for_status() soup = BeautifulSoup(response.text, "html.parser") return " ".join([p.text for p in soup.find_all("p")]) # Extract paragraph text except requests.RequestException: return "" # Fail gracefully by returning an empty string def get_domain_trust(self, url: str, content: str) -> int: """ Computes the domain trust score based on available data sources. """ trust_scores = [] if content: try: trust_scores.append(self.get_domain_trust_huggingface(content)) except: pass return int(sum(trust_scores) / len(trust_scores)) if trust_scores else 50 def get_domain_trust_huggingface(self, content: str) -> int: """ Uses a Hugging Face fake news detection model to assess credibility. """ if not content: return 50 # Default score if no content available result = self.fake_news_classifier(content[:512])[0] # Process only first 512 characters return 100 if result["label"] == "REAL" else 30 if result["label"] == "FAKE" else 50 def compute_similarity_score(self, user_query: str, content: str) -> int: """ Computes semantic similarity between user query and page content. """ if not content: return 0 return int(util.pytorch_cos_sim(self.similarity_model.encode(user_query), self.similarity_model.encode(content)).item() * 100) def check_facts(self, content: str) -> int: """ Cross-checks extracted content with Google Fact Check API. """ if not content: return 50 api_url = f"https://toolbox.google.com/factcheck/api/v1/claimsearch?query={content[:200]}" try: response = requests.get(api_url) data = response.json() return 80 if "claims" in data and data["claims"] else 40 except: return 50 # Default uncertainty score def check_google_scholar(self, url: str) -> int: """ Checks Google Scholar citations using SerpAPI. """ serpapi_key = self.serpapi_key params = {"q": url, "engine": "google_scholar", "api_key": serpapi_key} try: response = requests.get("https://serpapi.com/search", params=params) data = response.json() return min(len(data.get("organic_results", [])) * 10, 100) # Normalize except: return 0 # Default to no citations def detect_bias(self, content: str) -> int: """ Uses NLP sentiment analysis to detect potential bias in content. """ if not content: return 50 sentiment_result = self.sentiment_analyzer(content[:512])[0] return 100 if sentiment_result["label"] == "POSITIVE" else 50 if sentiment_result["label"] == "NEUTRAL" else 30 def get_star_rating(self, score: float) -> tuple: """ Converts a score (0-100) into a 1-5 star rating. """ stars = max(1, min(5, round(score / 20))) # Normalize 100-scale to 5-star scale return stars, "⭐" * stars def generate_explanation(self, domain_trust, similarity_score, fact_check_score, bias_score, citation_score, final_score) -> str: """ Generates a human-readable explanation for the score. """ reasons = [] if domain_trust < 50: reasons.append("The source has low domain authority.") if similarity_score < 50: reasons.append("The content is not highly relevant to your query.") if fact_check_score < 50: reasons.append("Limited fact-checking verification found.") if bias_score < 50: reasons.append("Potential bias detected in the content.") if citation_score < 30: reasons.append("Few citations found for this content.") return " ".join(reasons) if reasons else "This source is highly credible and relevant." def rate_url_validity(self, user_query: str, url: str) -> dict: """ Main function to evaluate the validity of a webpage. """ content = self.fetch_page_content(url) domain_trust = self.get_domain_trust(url, content) similarity_score = self.compute_similarity_score(user_query, content) fact_check_score = self.check_facts(content) bias_score = self.detect_bias(content) citation_score = self.check_google_scholar(url) final_score = ( (0.3 * domain_trust) + (0.3 * similarity_score) + (0.2 * fact_check_score) + (0.1 * bias_score) + (0.1 * citation_score) ) stars, icon = self.get_star_rating(final_score) explanation = self.generate_explanation(domain_trust, similarity_score, fact_check_score, bias_score, citation_score, final_score) return { "raw_score": { "Domain Trust": domain_trust, "Content Relevance": similarity_score, "Fact-Check Score": fact_check_score, "Bias Score": bias_score, "Citation Score": citation_score, "Final Validity Score": final_score }, "stars": { "score": stars, "icon": icon }, "explanation": explanation } # Streamlit app st.write("# LEVEL1 TITLE: APP") # Title for level 1 st.write("This is my first app") # Description # User input fields user_prompt = st.text_input("Enter your search query:", "I have just been on an international flight, can I come back home to hold my 1-month-old newborn?") url_to_check = st.text_input("Enter the URL to validate:", "https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/expert-answers/air-travel-with-infant/faq-20058539") # Run validation when the button is clicked if st.button("Validate URL"): if not user_prompt.strip() or not url_to_check.strip(): st.warning("Please enter both a search query and a URL.") else: with st.spinner("Validating URL..."): # Instantiate the URLValidator class validator = URLValidator() result = validator.rate_url_validity(user_prompt, url_to_check) # Display results in JSON format st.subheader("Validation Results") st.json(result)